Various machines, such as mining trucks, are known to employ drive propulsion systems to propel or retard the machine, such as a mechanical drive or an electric drive. An electric drive propulsion system, for example, generally includes an alternator, or other electrical power generator, driven by an internal combustion engine. The alternator, in turn, supplies electrical power to one or more electric drive motors connected to wheels of the machine. The motors are generally connected to the wheels by way of a final drive assembly that reduces the rotational speed of the motor. The final drive of a machine may employ one or more planetary gear sets to reduce the output speed of the propulsion system. Such planetary gear sets may include a planetary gear reduction stage having a non-rotating carrier. Such planetary gear reduction stages may include one ore more planetary gears that are less than fully submerged in an oil bath. There exists a need to lubricate and/or cool such planetary gears.
Some final drive assemblies may provide systems that pump oil to such planetary gears by way of supply lines, such as the lubrication system disclosed in U.S. patent application having Ser. No. 12/152,172, filed May 13, 2008 by Kabrick et al. However, such lubrication systems may add additional expense and complexity to machines, and may require the use of energy to drive the lubrication pumps.